1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device, and a molding die.
2. Description of the Related Art
As a related technique, Japanese Patent Laid-Open No. 2004-96094 describes an invention of a molding die for seal-molding a BGA (Ball Grid Array) package with molding resin.
The molding die causes a ceiling face of a cavity to bulge at an upper part of a semiconductor chip, and by joining the ceiling face of the cavity to the molding resin while curving a heat sink (heat spreader), prevents warpage of a semiconductor substrate due to shrinkage of the molding resin over time.
To this end, during seal-molding of the semiconductor chip, an inner face of the cavity of an upper molding die is shaped as an upward convex and an adsorption hole opposing the center of the heat spreader is vacuum-suctioned to bend the heat spreader so that the center of the heat spreader bulges and curves fully.
Japanese Patent Laid-Open No. 2000-349203 describes an invention of a so-called flip-chip semiconductor device which improves the joint strength between molding resin and a heat spreader by forming, in advance, asperities around an area that abuts a flip chip among a bottom face of the heat spreader (particularly, refer to FIG. 11 of Japanese Patent Laid-Open No. 2000-349203).
While the invention described in Japanese Patent Laid-Open No. 2004-96094 is arranged to absorb an overall shrinkage of the molding resin by deflecting the entire heat spreader in a bow-shape, the invention is incapable of producing sufficient adhesion between the heat spreader and the molding resin.
The invention described in Japanese Patent Laid-Open No. 2000-349203 relates to a flip-chip semiconductor device. Accordingly, the heat spreader is joined to an upper face of the flip chip and asperities are only formed on a part thereof. In addition, the molding resin does not seal the entire flip chip and the joining pressure between the heat spreader and the molding resin is generally not high. Therefore, even with the invention of Japanese Patent Laid-Open No. 2000-349203, sufficient adhesion between the heat spreader and the molding resin cannot be obtained.